When a California county wanted to encourage residents to buy health insurance earlier this year, officials employed a time-tested tactic for generating interest: nudity.

The Alameda County Social Services Agency’s ad campaign featured bare-skinned people who held up signs in strategic spots that read, “Cover your family.”

The use of naked people in ads about health care underscores the desperation felt by organizations and government entities that want to encourage enrollment as the launch of new coverage under the 2010 health care law approaches. On Oct. 1, people all over the nation can start signing up for coverage, which kicks in on Jan. 1, 2014.

One big question is whether uninsured people — especially healthy people — will get coverage or whether they’ll just pay a penalty for going without it, which in 2014 will be $95. That’s particularly true for young men without many medical needs, whose premiums will essentially subsidize everyone else. And if healthy people don’t sign up, then rates will be higher than they otherwise would be.

Enroll America — a nonprofit that hopes to spend more than $100 million to encourage people to sign up — is going after those men with a bank-shot strategy. The group plans to get out information not only to young guys but also to their nagging moms.

The Department of Health and Human Services needs all the help it can get from Enroll America and others to supplement federal and state efforts to attract interest. Federal officials say they will do all they can to reach out to uninsured people — from asking celebrities to plug the coverage on social media sites to sending details to churches to posting info on other agency websites.

But the HHS administrative budget was hit by a more than 5 percent annualized cut from the across-the-board sequester that took effect March 1. Cash-strapped federal officials also will run the new marketplaces in 26 states themselves, rather than handing the job to state officials. That’s more than originally envisioned.

Signing up the uninsured is a huge challenge that will require campaign-style tactics, said Enroll America President Anne Filipic, a former Democratic National Committee deputy executive director and 2008 Obama campaign field director.

Filipic most recently was deputy director of the White House Office of Public Engagement, working for Jon Carson. Carson now oversees Organizing for Action, the new iteration of the Obama campaign community-building group Organizing for America, which also will encourage people without insurance to buy it.

Enroll America was started with a push from the consumer group Families USA. The organization is funded by a wide range of groups, including health care industry officials with a stake in the success of enrollment such as hospitals, insurers, community health centers, Planned Parenthood women’s health centers, drug companies and major pharmacy chains. Many industry groups also are funding their own individual efforts to expand coverage, either through outreach or by creating separate local lobbying coalitions to convince state officials to expand Medicaid.

Enroll America hopes to build a list of potentially uninsured people, Filipic said. The organization will first target areas that have high rates of uninsurance, such as parts of Texas and Florida. Then it will use marketing and demographic data to zero in on folks who fit the profile of the uninsured, including lower-income people. The group plans to run surveys to further identify people who might be uninsured and could benefit from direct contact or information left in neighborhood shops, Filipic said.

She said she wants to explore ways that health care industry officials in the coalition might provide information to guide the group’s efforts to narrow the list of people who might be uninsured, although the group will be careful to avoid violating privacy laws.

Other groups are targeting young people with tactics that worked in the past. Calling on sports heroes is a popular technique. When Massachusetts expanded coverage, the state persuaded the 2006 Boston Red Sox to tout the new benefits. The Maryland advocacy group Health Care for All has used Ravens and Redskins players to promote Medicaid coverage, and an official said they will work together again. Vermont wants to deputize hockey players.

One question is whether federal officials are doing enough now to prepare for a publicity campaign later this summer and fall. The timing is tricky because government officials can’t yet give the public specific details such as what the coverage will cost, which insurance companies will offer benefits or which doctors will participate.

Without those details, consumers who hear about the coverage could become confused or frustrated. Marilyn Tavenner, acting administrator for the Centers for Medicare and Medicaid Services, said recently that outreach will really begin in July.

“It’s a very busy year, and I think we have all of the steps in place to get it done,” Tavenner told the Federation of American Hospitals at its conference. “But we are going to need your help.”

When CMS officials were preparing in 2005 to launch the comprehensive Medicare drug benefit the following year, then-administrator Mark McClellan and other officials traveled around the country in the spring to persuade local groups to help with enrollment. In June 2005, the officials began a bus tour to raise public awareness.

The drug benefit implementation was a big endeavor, but the current rollout is clearly more complex.

“You can never do enough,” McClellan said. “Even with clear deadlines and a lot of enrollment support, there will be a lot of people who just don’t get around to signing up. The more that can be done early, the better. From that standpoint, because it is such a challenge, there is definitely more to be done.”